Leaking battery?

Hello, this is what happened so far. I was using my Nitecore SRT3. The light shut off while in use. I assumed it was a low battery, then put it in the charger some time later. It read 3.15V, and took it out at 4.15V. As I was taking the battery out, I noticed something on my fingers. It was like a oily, clear film which I think came off from the side of the battery. Would that be a sign of something leaking? The battery is an AW 14500 protected battery. I want to play it safe before putting it back in the flashlight. Thank you.

Tried to do some more research and apparently leaking li ion has some sort of distinct smell to it. Not noticing anything so I guess I'm safe? I was scared to touch the thing for a few days. I still don't know what this thing is coming off the wrapper. Is it normal for some kind of film to develop from the wrapper? Possibly caused by the heat from charging? It does look like a top clear layer is starting to peel off from the rest.